| Universal mold vacuum system -> Monitor Keywords |
|
|
  Universal mold vacuum systemUSPTO Application #: 20070021862Title: Universal mold vacuum system Abstract: A controller for a mold vacuum unit uses a programmable logic controller to provide flexible translation of pre-existing signals present on the injection-molding machine avoiding the need for modification of that machine by the addition of limit switches or the like. Simple adjustment of real time of time delays is provided by the integration of two self-contained timer units working in conjunction with the fixed programming of the programmable logic controller. Removable memories for the programmable logic controller allow the vacuum unit to be used with a variety of different injection-molding machines (end of abstract)
Agent: Boyle Fredrickson Newholm Stein & Gratz, S.c. - Milwaukee, WI, US Inventor: Steven P. Kolander USPTO Applicaton #: 20070021862 - Class: 700200000 (USPTO) Related Patent Categories: Data Processing: Generic Control Systems Or Specific Applications, Specific Application, Apparatus Or Process, Product Assembly Or Manufacturing, Particular Manufactured Product Or Operation, Molding, Injection The Patent Description & Claims data below is from USPTO Patent Application 20070021862. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] - - - STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] - - - BACKGROUND OF THE INVENTION [0003] The present invention relates to injection molding machines and in particular to vacuum systems for such injection-molding machines. [0004] Injection-molding injects heated thermoplastic material at high pressures from an injector into a mold. The thermoplastic material cools within the mold and the mold may be opened and the part ejected. [0005] Gas trapped in the mold during the injection process may escape through the mold seams or through vents provided for that purpose. Alternatively, it is well known to apply a vacuum to the mold during the injection process to reduce gas entrapment. U.S. Pat. No. 4,573,900 entitled: Evacuation System for Injection-molding Machines, hereby incorporated by reference, describes a timer system controlling a pneumatic vacuum pump that may be used first, to apply a vacuum to the mold during certain periods of the injection cycle and second, to apply a positive pressure from the pneumatic line to the mold creating a "blow back" to assist in part ejection. [0006] Standard machines normally employ proprietary control systems that do not provide control signals to activate the vacuum system at the proper time and duration. Accordingly, it is known in the art to attach mechanical limit switches to the mold and its associated clamping mechanism to create the necessary signals from mechanical movement of the mold elements. [0007] This approach may not be suitable for creating more sophisticated vacuum control signals triggered by events or states not associated with a change in mold position, for example, as may occur in some two-shot molding applications. Modification of the standard injection-molding machine to attach the limit switches not envisioned by the manufacturer can be difficult and the limit switches, once in place, are subject to damage and contamination. BRIEF SUMMARY OF THE INVENTION [0008] The present invention provides a mold vacuum system that employs a programmable logic controller to translate pre-existing control signals used or created by the standard injection-molding machine into the necessary vacuum control signals. In one important application, the programmable logic controller receives signals from the interface on the standard injection-molding machine used for coordination of the injection-molding machine with robotic or automated parts handling system. This interface provides some standardization and documentation. [0009] The programmable logic controller may be flexibly programmed for complex logical combinations of existing signals to eliminate the need for special limit switches. Further, replaceable memory cartridges for the programmable logic controller allow ready transfer of the mold vacuum system among machines by switching the memory as a "personality module". [0010] In one embodiment, the programmable logic controller may work with standard electronic timers, the latter which provide a simple and familiar method of varying timing parameters in real-time without the drawbacks of connecting a programming terminal to the programmable logic controller. [0011] Specifically then, the present invention provides a vacuum system for a standard injection-molding machine having an injector unit, a mold clamp unit, and an injection-molding controller producing control signals controlling the injector unit and mold clamp unit. The vacuum system includes an interface cable connectable to the control signals of the injection-molding controller and a programmable logic controller receiving the control signals from the interface cable and executing a stored program to derive vacuum timing signals from at least some of the control signals. A vacuum pump and valve assembly receives vacuum timing signals from the programmable logic controller to provide vacuum on a vacuum line to a mold. [0012] It is thus one object of at least one embodiment of the invention to provide a control of a vacuum system without the need to install mechanical limit switches or otherwise modify the injection-molding machine. It is another object of at least one embodiment of the invention to allow arithmetic and logical combinations of standard injection-molding controller signals to provide more sophisticated vacuum control. [0013] The vacuum system may include at least one electronic timer having an integral programming panel, the electronic timer communicating with the programmable logic controller to provide a timing function for the vacuum timing signal. [0014] It is thus another object of at least one embodiment of the invention to incorporate standalone timers into the vacuum system, despite the presence of timing functions within the programmable logic controller, to provide a familiar interface to the user that allows simple, real-time modification of the operation of the vacuum system without a programming terminal. [0015] The programmable logic controller may provide the vacuum timing signal to the electronic timer where it is delayed and then passed to the vacuum pump and valve assembly. [0016] It is thus another object of at least one embodiment of the invention to provide an interface between the timers and the programmable logic controller that does not require communication of a timing value to the programmable logic controller. [0017] The timing function may be the duration of the application and vacuum to the mold. [0018] Thus it is another object to the invention to provide ready accessibility to a parameter that typically must be adjusted for a given mold while employing the programmable logic controller to handle parameters that vary only among injection-molding machines. [0019] The vacuum system may include a terminal block receiving the interface cable and providing terminals releasably holding wires communicating with the programmable logic controller and the timer. [0020] It is thus another object of at least one embodiment of the invention to allow highly flexible interconnection among the control signals, the programmable logic controller and the timers. Continue reading... Full patent description for Universal mold vacuum system Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Universal mold vacuum system patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Universal mold vacuum system or other areas of interest. ### Previous Patent Application: Numerical controller Next Patent Application: Method and system for replenishing inventory items Industry Class: Data processing: generic control systems or specific applications ### FreshPatents.com Support Thank you for viewing the Universal mold vacuum system patent info. IP-related news and info Results in 0.81446 seconds Other interesting Feshpatents.com categories: Canon USA , Celera Genomics , Cephalon, Inc. , Cingular Wireless , Clorox , Colgate-Palmolive , Corning , Cymer , |
||
